This is a remix from https://www.thingiverse.com/thing:398515 When I was printing the very nice tower from gaaZolee, I found that the tower flexed somewhat during printing especially at the higher levels / cooler temperatures. This led to an artificially worse print for the given temperature as the imprecision was partially caused by the moment arm of the horizontal force of the printer's drag along the top multiplied by the height. The solution is to increase the size and girth of the tower, but that opposes gaaZolee's original purpose was a quickly printed tower that tests for the correct temperature. Since I-beams stiffen beams with a minimal amount of material, I decided to create a wider, stiffer tower by using I-beams. The trick was how to do this without defeating all the detailed torture tests gaaZolee put in the original design. Secondly, the added re-enforcement needed to repeat on stacked layers to retain the benefit of the I-beam all the way up. I attempted this by adding a cross beam between the cylindrical hole and also by extending the side of the bridging with no gap. In order to control the temperature for each level, follow directions and links given by gaaZolee. I used the Macro function in Cura's "Extensions->Post Processing -> Modify G-Code" as shown below to set the temperature for each level. Note that the spacing on each level is the same as gaaZolee's.